A 3-D Encryption Technique Using Computer-Generated Hologram

The techniques of hologram for encryption and decryption have been widely researched and applied. Almost all the information of encryption is 2-D image. Parameters (wave length, recording distance, incidence angle, etc.) are regarded as the encoded keys for encryption and decryption. In the paper a novel way to encrypt 3-D information is proposed, which is based on technique of virtual optics. A new encoded key is introduced into security hologram, the size of 3-D object, which may play an important role for better protection against counterfeiting. Furthermore, a new image quality assessment is proposed to estimate the reconstruction 3-D object of CGH called Modified PSNR (peak signal-to-noise ratio). Simulation experiments show that CGH is an effective encryption technique, and Modified PSNR is a proper definite quantity analysis method for 3-D imaging.